I’d worked out a workaround recently; I was a bit miffed when they (seemingly) fixed it 
The problem was that when you enter the approach, the sim inserts USR as the starting point. By the time you’ve pressed insert, you’ve passed USR and (and this is the bug) the plane flies back to it to start the approach.
My workaround was, on being given the approach, press Active Pause, insert the approach, then un-pause. The sim sees you’re still at USR so it’s happy.
But I’ve not experienced the bug since SU9.